Long-term Average Spectrum Research Articles

High-Frequency Audibility: The Effects of Audiometric Configuration, Stimulus Type, and Device

For the last decade, the importance of providing amplification up to 9-10 kHz has been supported by multiple studies involving children and adults. The extent to which a listener with hearing loss can benefit from bandwidth expansion is dependent on the audibility of high-frequency cues. The American National Standards Institute (ANSI) devised a standard method for measuring and reporting hearing aid bandwidth for quality-control purposes. However, ANSI bandwidth measurements were never intended to reflect the true frequency range that is audible for a speech stimulus for a person with hearing loss. The purpose of this study was to (1) determine the maximum audible frequency of conventional hearing aids using a speech signal as the input through the hearing aid microphone for different degrees of hearing loss, (2) examine how the maximum audible frequency changes when the input stimulus is presented through hearing assistance technology (HAT) systems with cross-coupling of manufacturers' transmitters and receivers, and (3) evaluate how the maximum audible frequency compares with the upper limit of the ANSI bandwidth measure. Eight behind-the-ear hearing aids from five hearing aid manufacturers were selected based on a range of ANSI bandwidth upper frequency limits. Three audiometric configurations with varied degrees of high-frequency hearing loss were programmed into each hearing aid. Hearing aid responses were measured with the International Speech Test Signal (ISTS), broadband noise, and a short speech token (/asa/) as stimuli presented through a loudspeaker. HAT devices from three manufacturers were used to create five HAT scenarios. These instruments were coupled to the hearing aid programmed for the audiogram that provided the highest maximum audible frequency in the hearing aid analysis. The response from each HAT scenario was obtained using the same three stimuli as during the hearing aid analysis. All measurements were collected in an audiometric sound booth on a Knowles Electronic Manikin for Acoustic Research (KEMAR). A custom computer program was used to record responses from KEMAR. Maximum audible frequency was defined as the highest point where the Long-Term Average Speech Spectrum (LTASS) intersected the audiogram. The average maximum audible frequency measured through KEMAR ranged from 3.5 kHz to beyond 8 kHz and varied significantly across devices, audiograms, and stimuli. The specified upper limit of the ANSI bandwidth was not predictive of the maximum audible frequency across conditions. For most HAT systems, the maximum audible frequency for the hearing aid plus HAT condition was equivalent to the hearing aid for the same measurement configuration. In some cases, however, the HAT system imposed a lower maximum audible frequency than the hearing aid-only condition. The maximum audible frequency of behind-the-ear hearing aids is dependent on the degree of hearing loss, amplification device, and stimulus input. Estimating the maximum audible frequency by estimating the frequency where the speech spectrum intersects the audiogram in the high frequencies can assist clinicians in making decisions about which device or configuration of devices provides the greatest access to high-frequency information, as well as whether frequency-lowering technology should be used.

Computerized analysis of acoustic characteristics of patients with internal nasal valve collapse before and after functional rhinoplasty

Acoustic analysis of sounds produced during speech provides significant information about the physiology of larynx and vocal tract. The analysis of voice power spectrum is a fundamental sensitive method of acoustic assessment that provides valuable information about the voice source and characteristics of vocal tract resonance cavities. The changes in long-term average spectrum (LTAS) spectral tilt and harmony to noise ratio (HNR) were analyzed to assess the voice quality before and after functional rhinoplasty in patients with internal nasal valve collapse. Before and 3 months after functional rhinoplasty, 12 participants were evaluated and HNR and LTAS spectral tilt in /a/ and /i/ vowels were estimated. It was seen that an increase in HNR and a decrease in LTAS spectral tilt existed after surgery. Mean LTAS spectral tilt in vowel /a/ decreased from 2.37 ± 1.04 to 2.28 ± 1.17 (P = 0.388), and it was decreased from 4.16 ± 1.65 to 2.73 ± 0.69 in vowel /i/ (P = 0.008). Mean HNR in the vowel /a/ increased from 20.71 ± 3.93 to 25.06 ± 2.67 (P = 0.002), and it was increased from 21.28 ± 4.11 to 25.26 ± 3.94 in vowel /i/ (P = 0.002). Modification of the vocal tract caused the vocal cords to close sufficiently, and this showed that although rhinoplasty did not affect the larynx directly, it changes the structure of the vocal tract and consequently the resonance of voice production. The aim of this study was to investigate the changes in voice parameters after functional rhinoplasty in patients with internal nasal valve collapse by computerized analysis of acoustic characteristics.

Spectral motion contrast as a speech context effect.

Spectral contrast effects may help "normalize" the incoming sound and produce perceptual constancy in the face of the variable acoustics produced by different rooms, talkers, and backgrounds. Recent studies have concentrated on the after-effects produced by the long-term average power spectrum. The present study examined contrast effects based on spectral motion, analogous to visual-motion after-effects. In experiment 1, the existence of spectral-motion after-effects with word-length inducers was established by demonstrating that the identification of the direction of a target spectral glide was influenced by the spectral motion of a preceding inducer glide. In experiment 2, the target glide was replaced with a synthetic sine-wave speech sound, including a formant transition. The speech category boundary was shifted by the presence and direction of the inducer glide. Finally, in experiment 3, stimuli based on synthetic sine-wave speech sounds were used as both context and target stimuli to show that the spectral-motion after-effects could occur even with inducers with relatively short speech-like durations and small frequency excursions. The results suggest that spectral motion may play a complementary role to the long-term average power spectrum in inducing speech context effects.

Development of Mandarin tonal identification in noise test materials

The aim of this study was to develop comprehensive test material for Mandarin tone identification in noise (M-TINT) based on the linguistic characteristics in Chinese. In keeping with both the reliability and efficiency in clinical practice, a primary list consisted of 320 words(80 syllables in four tones each) was designed according to the following principles: shortness of the lists, word familiarity and with a meaning in all four tones. The digital sound file was recorded by a male speaker and a female speaker (both of them are radio broadcaster). The tonal identification material database, which included 288 items (72 loudness-balanced syllables in all 4 Mandarin tones) was established by digital filler and balanced for equal loudness. The complete material was recorded in two CDs in a male version and a female version. The speaker-specific masking noises were generated by filtering Gaussian white noise to the speaker's long-term average speech spectrum (LTASS) and by scaling the masking noises to the same RMS amplitudes, as those of the speech, in order to acquire the effective sound masking. The speaker-specific masking noises could be able or disable during the word presentation. The sound pressure level could be selected concerning on the test setting. The mandarin tonal identification materials were designed by both the tonal acoustic properties and the psychophysics characteristic of adults. It is an useful speech test in clinical work and research, and can potentially be used as the basic list for other tonal language identification test in the future.

Acoustic markers to differentiate gender in prepubescent children's speaking and singing voice

ObjectivesInvestigation sought to determine whether there is any acoustic variable to objectively differentiate gender in children with normal voices. MethodsA total of 30 children, 15 boys and 15 girls, with perceptually normal voices were examined. They were between 7 and 10 years old (mean: 8.1, SD: 0.7 years). Subjects were required to perform the following phonatory tasks: (1) to phonate sustained vowels [a:], [i:], [u:], (2) to read a phonetically balanced text, and (3) to sing a song. Acoustic analysis included long-term average spectrum (LTAS), fundamental frequency (F0), speaking fundamental frequency (SFF), equivalent continuous sound level (Leq), linear predictive code (LPC) to obtain formant frequencies, perturbation measures, harmonic to noise ratio (HNR), and Cepstral peak prominence (CPP). Auditory perceptual analysis was performed by four blinded judges to determine gender. ResultsNo significant gender-related differences were found for most acoustic variables. Perceptual assessment showed good intra and inter rater reliability for gender. Cepstrum for [a:], alpha ratio in text, shimmer for [i:], F3 in [a:], and F3 in [i:], were the parameters that composed the multivariate logistic regression model to best differentiate male and female children's voices. ConclusionSince perceptual assessment reliably detected gender, it is likely that other acoustic markers (not evaluated in the present study) are able to make clearer gender differences. For example, gender-specific patterns of intonation may be a more accurate feature for differentiating gender in children's voices.

Speech-on-speech masking with variable access to the linguistic content of the masker speech for native and nonnative english speakers.

Masking release for an English sentence-recognition task in the presence of foreign-accented English speech compared with native-accented English speech was reported in Calandruccio et al (2010a). The masking release appeared to increase as the masker intelligibility decreased. However, it could not be ruled out that spectral differences between the speech maskers were influencing the significant differences observed. The purpose of the current experiment was to minimize spectral differences between speech maskers to determine how various amounts of linguistic information within competing speech Affiliationect masking release. A mixed-model design with within-subject (four two-talker speech maskers) and between-subject (listener group) factors was conducted. Speech maskers included native-accented English speech and high-intelligibility, moderate-intelligibility, and low-intelligibility Mandarin-accented English. Normalizing the long-term average speech spectra of the maskers to each other minimized spectral differences between the masker conditions. Three listener groups were tested, including monolingual English speakers with normal hearing, nonnative English speakers with normal hearing, and monolingual English speakers with hearing loss. The nonnative English speakers were from various native language backgrounds, not including Mandarin (or any other Chinese dialect). Listeners with hearing loss had symmetric mild sloping to moderate sensorineural hearing loss. Listeners were asked to repeat back sentences that were presented in the presence of four different two-talker speech maskers. Responses were scored based on the key words within the sentences (100 key words per masker condition). A mixed-model regression analysis was used to analyze the difference in performance scores between the masker conditions and listener groups. Monolingual English speakers with normal hearing benefited when the competing speech signal was foreign accented compared with native accented, allowing for improved speech recognition. Various levels of intelligibility across the foreign-accented speech maskers did not influence results. Neither the nonnative English-speaking listeners with normal hearing nor the monolingual English speakers with hearing loss benefited from masking release when the masker was changed from native-accented to foreign-accented English. Slight modifications between the target and the masker speech allowed monolingual English speakers with normal hearing to improve their recognition of native-accented English, even when the competing speech was highly intelligible. Further research is needed to determine which modifications within the competing speech signal caused the Mandarin-accented English to be less effective with respect to masking. Determining the influences within the competing speech that make it less effective as a masker or determining why monolingual normal-hearing listeners can take advantage of these differences could help improve speech recognition for those with hearing loss in the future.

Importance of envelope modulations during consonants and vowels in segmentally interrupted sentences

The present study investigated the importance of overall segment amplitude and intrinsic segment amplitude modulation of consonants and vowels to sentence intelligibility. Sentences were processed according to three conditions that replaced consonant or vowel segments with noise matched to the long-term average speech spectrum. Segments were replaced with (1) low-level noise that distorted the overall sentence envelope, (2) segment-level noise that restored the overall syllabic amplitude modulation of the sentence, and (3) segment-modulated noise that further restored faster temporal envelope modulations during the vowel. Results from the first experiment demonstrated an incremental benefit with increasing resolution of the vowel temporal envelope. However, amplitude modulations of replaced consonant segments had a comparatively minimal effect on overall sentence intelligibility scores. A second experiment selectively noise-masked preserved vowel segments in order to equate overall performance of consonant-replaced sentences to that of the vowel-replaced sentences. Results demonstrated no significant effect of restoring consonant modulations during the interrupting noise when existing vowel cues were degraded. A third experiment demonstrated greater perceived sentence continuity with the preservation or addition of vowel envelope modulations. Overall, results support previous investigations demonstrating the importance of vowel envelope modulations to the intelligibility of interrupted sentences.

Long-Term Average Spectra of Adult Iranian Speakers' Voice

Long-term average spectrum (LTAS) allows quantifying the voice quality and provides an overview of the mean spectral characteristics of a voice. The aims of this study were to survey normal spectral characteristics of Persian and investigate sex-related changes in the source characteristics of dynamic speech using LTAS. Speech samples obtained from 30 male and 30 female Persian-speaking participants reading a text in habitual pitch and loudness level. At the LTAS window and using Praat software, the amplitude values were obtained at equal intervals of 160 Hz, ranging from 0 to 8 kHz. The main features of the average spectrum were as follows: peak in the region of 480 Hz with a reduction at higher frequencies, a 20 dB decline from 480 to 960 Hz, a flat region from 960 to 1920 Hz, a further decline from 1920 to 3040 Hz, and a further flat region from 3040 to 8000 Hz. In comparison to men, women revealed significant lower levels of amplitude at frequencies of 160 and 320 Hz and higher levels of amplitude at frequencies of 960, 3360, 3520, 3680, 3840, and 5920 Hz. The overall shape and gender-related energy distribution pattern of the LTAS of Persian were more similar to those of English than to those of Korean. The more phonetic differences between Persian and Korean compared with Persian and English might contribute to different spectral characteristics. The present study tried to clarify the spectral characteristics of Iranian male and female voices and focused on more breathy voice quality for women than men.

Long-term-average spectrum characteristics of Kunqu Opera singers’ speaking, singing and stage speech

Long-term-average spectrum (LTAS) characteristics were analyzed for ten Kunqu Opera singers, two in each of five roles. Each singer performed singing, stage speech, and conversational speech. Differences between the roles and between their performances of these three conditions are examined. After compensating for Leq difference LTAS characteristics still differ between the roles but are similar for the three conditions, especially for Colorful face (CF) and Old man roles, and especially between reading and singing. The curves show no evidence of a singer's formant cluster peak, but the CF role demonstrates a speaker's formant peak near 3 kHz. The LTAS characteristics deviate markedly from non-singers’ standard conversational speech as well as from those of Western opera singing.

Acoustic Characteristics of Male Commercial and Public Radio Broadcast Voices

Radio broadcasters need to have a voice that suits the station, which employs them. The aim of this study was to determine whether there are any acoustic measures that reflect differences between male broadcasters, who use their voices on commercial and public radio stations, and nonbroadcasting, male controls. Male commercial (n = 4) and public (n = 11) broadcasters and two groups of male, age-matched controls were recorded while reading the "Rainbow Passage" as if presenting on radio. Reading productions were analyzed for equivalent sound level (L(eq)), two measures of the long-term average spectrum and two measures of cepstral peak prominence. A two-group (ie, commercial vs public) by two-paired (broadcaster/matching control) analysis of variance was performed for each measure. An interaction effect was observed such that commercial broadcasters had a higher peak in speaker's formant (SF) region and lower alpha ratio (AR) (lower level difference between 0 and 1 k Hz and 1 and 4 kHz ranges) than public broadcasters and controls. Post hoc discriminant function analyses showed that AR could predict whether a radio performer worked on commercial or public radio network to 81% accuracy (R(2) = 0.810, P < 0.001). Commercial broadcasters have a more prominent peak in the SF region and smaller AR than public broadcasters and controls, similar to levels documented in actors. Given these features were not found in the public broadcasters and either control group, these results indicate that voice quality requirements for broadcasters may distinctly differ based on their station of employment. Further research with a larger sample size is required to validate this hypothesis.

CHENFIT-AMP, A Nonlinear Fitting and Amplification Strategy for Cochlear Hearing Loss

CHENFIT-AMP is a novel nonlinear strategy that combines the fitting (gain prescription) and amplification (gain implementation) procedures for cochlear hearing loss. The fitting part of CHENFIT-AMP prescribes gain for outer hair cell (OHC) and inner hair cell (IHC) loss, respectively. The gain for OHC loss varies with the cochlear gain decided by the value of OHC loss and the input level. The gain for IHC loss varies with the value of IHC loss only and will be limited to a constant if there is a "dead region." The amplification part of CHENFIT-AMP is responsible for estimating the input level and cochlear gain based on Chen's loudness model. CHENFIT-AMP is evaluated with four typical audiograms and nine individual audiograms. A widely used nonlinear fitting procedure, NAL-NL2, is evaluated to compare prescription results with CHENFIT-AMP; a standard nonlinear amplification algorithm, multichannel compression (MCC), with the parameters provided by NAL-NL2, is also evaluated to compare amplification results with CHENFIT-AMP. For long-term average speech spectrum (LTASS) inputs, CHENFIT-AMP generally prescribes similar gain as NAL-NL2 for the typical audiograms; however, gain prescribed by CHENFIT-AMP is more individualized than NAL-NL2 for the individual audiograms, especially when the audiograms have big deviations in the slope. For LTASS-shaped noise input, the gain implemented by MCC with parameters provided by NAL-NL2 cannot completely realize the gain prescribed by NAL-NL2. For speech sentence inputs, average ratings by subjects indicated that amplification by CHENFIT-AMP was preferred and led to a louder perception than that by MCC with parameters from NAL-NL2.

Subglottal Pressure Oscillations Accompanying Phonation

Acoustic and aerodynamic properties of the voice source and vocal tract have been extensively analyzed during the last half century. Corresponding investigations of the subglottal system are rare but can be assumed to be relevant to voice production. In the present exploratory study, subglottal pressure was recorded in a male adult subject by means of tracheal puncture. Also recorded were the oral airflow and audio signals. Effects of vowel, phonation type, and vocal register shifts on the subglottal pressure waveform were examined. The moment of maximum flow declination rate was synchronous with the main positive peak of the subglottal pressure waveform. The three lowest subglottal resonance frequencies, determined by inverse filtering and long-term average spectra of the subglottal pressure during speech, were found to be about 500, 1220, and 2000Hz, irrespective of supraglottal variations and phonation type. However, the subglottal pressure waveform was affected by the supraglottal formants, whereas the radiated vowel spectra did not show clear influence by the subglottal resonances. The fundamental frequency immediately preceding and immediately following a register break in pitch glides did not show systematic relationships with formants or with the lowest subglottal resonance.

Masking release due to linguistic and phonetic dissimilarity between the target and masker speech.

To investigate masking release for speech maskers for linguistically and phonetically close (English and Dutch) and distant (English and Mandarin) language pairs. Thirty-two monolingual speakers of English with normal audiometric thresholds participated in the study. Data are reported for an English sentence recognition task in English and for Dutch and Mandarin competing speech maskers (Experiment 1) and noise maskers (Experiment 2) that were matched either to the long-term average speech spectra or to the temporal modulations of the speech maskers from Experiment 1. Listener performance increased as the target-to-masker linguistic distance increased (English-in-English < English-in-Dutch < English-in-Mandarin). Spectral differences between maskers can account for some, but not all, of the variation in performance between maskers; however, temporal differences did not seem to play a significant role.

Initial Development of a Temporal-Envelope-Preserving Nonlinear Hearing Aid Prescription Using a Genetic Algorithm

Most hearing aid prescriptions focus on the optimization of a metric derived from the long-term average spectrum of speech, and do not consider how the prescribed values might distort the temporal envelope shape. A growing body of evidence suggests that such distortions can lead to systematic errors in speech perception, and therefore hearing aid prescriptions might benefit by including preservation of the temporal envelope shape in their rationale. To begin to explore this possibility, we designed a genetic algorithm (GA) to find the multiband compression settings that preserve the shape of the original temporal envelope while placing that envelope in the listener's audiometric dynamic range. The resulting prescription had a low compression threshold, short attack and release times, and a combination of compression ratio and gain that placed the output signal within the listener's audiometric dynamic range. Initial behavioral tests of individuals with impaired hearing revealed no difference in speech-in-noise perception between the GA and the NAL-NL2 prescription. However, gap detection performance was superior with the GA in comparison to NAL-NL2. Overall, this work is a proof of concept that consideration of temporal envelope distortions can be incorporated into hearing aid prescriptions.

Development of the speech test signal in Brazilian Portuguese for real-ear measurement

Objective: Recommended practice is to verify the gain and/or output of hearing aids with speech or speech-shaped signals. This study has the purpose of developing a speech test signal in Brazilian Portuguese that is electroacoustically similar to the international long-term average speech spectrum (ILTASS) for use in real ear verification systems. Design: A Brazilian Portuguese speech passage was recorded using standardized equipment and procedures for one female talker and compared to ISTS. The passage consisted of simple, declarative sentences making a total of 148 words. Study sample: The recordings of a Brazilian Portuguese passage were filtered to the ILTASS and compared to the International Speech Test Signal (ISTS). Aided recordings were made at three test levels, for three audiograms for the Brazilian Portuguese passage and the ISTS. Results: The unaided test signals were spectrally matched to within 0.5 dB. Aided evaluation revealed that the Brazilian Portuguese passage produced aided spectra that were within 1 dB on average, within about 2 dB per audiogram, and within about 3 dB per frequency for 95% of fittings. Conclusion: Results indicate that the Brazilian Portuguese passage developed in this study provides similar electroacoustic hearing-aid evaluations to those expected from the standard ISTS passage.

Examining the extent of anticipatory coronal coarticulation: A long-term average spectrum analysis

Phonetic studies of English liquids /r/ and /l/ have shown these consonants can exert strong coarticulatory effects on both adjacent and non-adjacent vowels. The studies of long-range coarticulation, however, have so far been limited to British English and have not explicitly compared liquids to other coronal consonants. The current study investigated local and long-range effects of coronals /l/, /r/, and /d/ in Canadian English. 14 speakers were recorded reading the sentences “We thought it might be(a) ram/lamb/dam/ham” repeatedly. Long-term average spectra of five vowels preceding the target consonants were calculated and compared to baseline values. The results revealed significant differences between the coronal consonants and the control (/h/) in up to five preceding syllables. Significant differences among the three coronals, however, were limited to the immediately preceding vowel. The other vowels showed some differences between /r/ and /d/, but not between /l/ and the other coronals. The results show that long-range coarticulation can spread for up to five syllables and involve both liquid and non-liquid coronals. The spectral differences between the two liquids in Canadian English, however, may not be as robust as have been reported for British English.

Immediate acoustic effects of straw phonation exercises in subjects with dysphonic voices

This study sought to measure any acoustic changes in the speaking voice immediately after phonation exercises involving plastic straws versus phonation exercises with the open vowel /a/. Forty-one primary school teachers with slightly dysphonic voices were asked to participate in four phonatory tasks. Phonetically balanced text at habitual intensity level and speaking fundamental frequency was recorded. Acoustical analysis with long-term average spectrum was performed. Significant changes after therapy for the experimental group include the alpha ratio, L1–L0 ratio and ratio between 1–5 kHz and 5–8 kHz. The results indicate that the use of phonatory tasks with straw exercises can have immediate therapeutic acoustic effects in dysphonic voices. Long-term effects were not assessed in this study.

Electroglottographic Analysis of Actresses and Nonactresses' Voices in Different Levels of Intensity

Previous studies with long-term average spectrum (LTAS) showed the importance of the glottal source for understanding the projected voices of actresses. In this study, electroglottographic (EGG) analysis was used to investigate the contribution of the glottal source to the projected voice, comparing actresses and nonactresses' voices, in different levels of intensity. Thirty actresses and 30 nonactresses sustained vowels in habitual, moderate, and loud intensity levels. The EGG variables were contact quotient (CQ), closing quotient (QCQ), and opening quotient (QOQ). Other variables were sound pressure level (SPL) and fundamental frequency (F0). A KayPENTAX EGG was used. Variables were inputted in a general linear model. Actresses showed significantly higher values for SPL, in all levels, and both groups increased SPL significantly while changing from habitual to moderate and further to loud. There were no significant differences between groups for EGG quotients. There were significant differences between the levels only for F0 and CQ for both groups. SPL was significantly higher among actresses in all intensity levels, but in the EGG analysis, no differences were found. This apparently weak contribution of the glottal source in the supposedly projected voices of actresses, contrary to previous LTAS studies, might be because of a higher subglottal pressure or perhaps greater vocal tract contribution in SPL. Results from the present study suggest that trained subjects did not produce a significant higher SPL than untrained individuals by increasing the cost in terms of higher vocal fold collision and hence more impact stress. Future researches should explore the difference between trained and nontrained voices by aerodynamic measurements to evaluate the relationship between physiologic findings and the acoustic and EGG data. Moreover, further studies should consider both types of vocal tasks, sustained vowel and running speech, for both EGG and LTAS analysis.

Influence on Spectral Energy Distribution of Emotional Expression

The aim of this study was to determine the influence of emotional expression in spectral energy distribution in professional theater actors. The study design is a quasi-experimental study. Thirty-seven actors, native Spanish speakers, were included. All subjects had at least 3 years of professional experience as a theater actor and no history of vocal pathology for the last 5 years. Participants were recorded during a read-aloud task of a 230-word passage, expressing six different emotions (happiness, sadness, fear, anger, tenderness, and eroticism) and without emotion (neutral state). Acoustical analysis with long-term average spectrum included three variables: the energy level difference between the F(1) and fundamental frequency (F(0)) regions, ratio between 1-5kHz and 5-8kHz, and alpha ratio. All the different emotions differ significantly from the neutral state for alpha ratio and 1-5/5-8kHz ratio. Only significant differences between "joy," "anger," and "eroticism" were found for L1-L0 ratio. Statistically significant differences between genders for the three acoustical variables were also found. The expression of emotion impacts the spectral energy distribution. On the one hand emotional states characterized by a breathy voice quality such as tenderness, sadness, and eroticism present a low harmonic energy above 1kHz, high glottal noise energy, and more energy on F(0) than overtones. On the other hand, emotional states such as joy, anger, and fear are characterized by high harmonic energy greater than 1kHz (less steep spectral slope declination), low glottal noise energy, and more energy on the F(1) than F(0) region.

An ultrasonographic study of lingual contortion speech

The present study evaluated global aspects of lingual movement and acoustics of speech with a contorted tongue. A male participant read four sentences from the Grandfather passage in a normal and three lingual contortion conditions. In the posterior contortion condition, the participant retracted his posterior tongue into the pharynx. In the anterior and posterior contortion conditions, this was combined with an anchoring of the tongue tip in the anterior floor of mouth. In the lateral contortion condition, the left side of the tongue was held along the lateral floor of mouth. Tongue movement in the midsagittal and the coronal planes was recorded with ultrasound, with parallel acoustic recordings. Analysis of average tongue speed in the midsagittal plane demonstrated different speed profiles for the contortion conditions. A principal component analysis yielded a protrusion/retraction and a dorsal height control component. In the lateral contortion condition, an additional component emerged. The analysis of the midsagittal groove from the coronal ultrasound demonstrated increased grooving in the posterior and the combined anterior and posterior contortion conditions. The lateral contortion led to an increase of convexity of the coronal tongue. The long-term average spectra demonstrated anti-resonances related to pharyngeal widening in the posterior and the combined anterior and posterior contortion conditions, as well as a decrease of high frequency components in all contortion conditions. The study offers first insights into tongue movement under different contortion conditions. Lingual contortion could serve as a paradigm for research about the plasticity of lingual movement in speech.